Skip to content
The Encyclopedia of Horology

Wristwatch · Automatic wristwatch

Jaeger-LeCoultre Master Mariner Chronometer Prototype Ref. 24002.42

Partially verified

This Jaeger-LeCoultre Master Mariner Chronometer is a stainless steel wristwatch from the 1970s, identified as a prototype. It features a 39mm case and is powered by the automatic caliber 906 movement. The dial is a silver linen-textured finish with applied indices and a date display window showing the day and date in French. The watch is presented on a leather strap. Its status as a prototype is suggested by the configuration of reference 24002.42, the movement's production chronology, and the case back engraving which reads "PROTOTYPE" and "UNSALEABLE HORS VENTE AUSSER VERKAUF". The auction description reports the watch as being in honest condition with surface wear consistent with age, and notes the dial texture is well-preserved.

Front view of the Jaeger-LeCoultre Master Mariner Chronometer prototype showing the silver linen dial and day-date aperture.
Front view of the Jaeger-LeCoultre Master Mariner Chronometer prototype showing the silver linen dial and day-date aperture. — Huntington Company. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
huntingtoncompany.com
Category
Wristwatch · Automatic wristwatch
Maker / attribution
Jaeger-LeCoultre
Reference
24002.42
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
circa 1970s
Source-reported place
Switzerland

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Design and Case

The watch features a stainless steel case measuring 39mm in diameter. This size was considered substantial for Jaeger-LeCoultre during the 1970s, reflecting a shift toward larger, more contemporary case designs. The case is described as having a broad profile that maintains its original definition, displaying surface wear consistent with its age and usage.

The dial is finished with a silver linen texture. This finish is designed to create subtle changes in appearance under different lighting conditions, adding depth to the watch face without the use of additional colors or decorations. The layout includes baton indices and a day-date aperture positioned at the 3 o'clock marker.

Evidence for this section
  • “At 39mm, the design was particularly substantial for the period.”
  • “The linen dial is particularly suited to the watch. Rather than relying on a flat surface, the fine texture changes subtly with the light and gives an otherwise restrained design considerably more depth.”
  • “Stainless steel case presents attractively with surface wear and marks consistent with age and use.”

Movement and Chronology

The piece is powered by an automatic caliber 906 movement. The movement number inside this specific watch correlates to a production timeframe of approximately 1972 to 1973.

This chronological data, combined with the unique reference 24002.42 designation, suggests that the watch belongs to a developmental or prototype stage for the Master Mariner line. The integration of this automatic movement was intended to balance practical timekeeping with the evolving larger proportions of 1970s wristwatch design.

Evidence for this section
  • “The automatic caliber 906 used throughout the reference 2400X Master Mariner family is generally associated with production around 1973 to 1975”
  • “movement number inside this watch corresponds with approximately 1972 to 1973.”
  • “Combined with the unusual reference 24002.42 configuration, the timing supports the possibility that this watch belongs to the developmental stage of the Master Mariner”

Prototype Attribution

The watch is categorized as a potential prototype. This attribution is supported by the specific text engraved on the case back, which includes the word "PROTOTYPE" alongside the phrases "UNSALEABLE," "HORS VENTE," and "AUSSER VERKAUF." These markings indicate the watch's status outside of standard production channels.

While the available evidence provides clues regarding its transitional nature, the source emphasizes that such prototype status should be viewed within the limits of historical information. The piece is treated as an object intended for further study rather than a standard production model.

Evidence for this section
  • “This example becomes considerably more interesting because it is believed to be a prototype.”
  • “The reference 24002.42 is interesting precisely because it invites further study.”

Open research questions

  • What is the specific movement serial number range for the 1972-1973 caliber 906 production?
  • Are there other known examples of the reference 24002.42 in public or private collections to compare against this prototype?

Source evidence

Recorded claims and source quotations for Jaeger-LeCoultre Master Mariner Chronometer Prototype Ref. 24002.42
FieldSource-reported valueSource quotation
BrandJaeger-LeCoultre“Jaeger-LeCoultre”
ModelMaster Mariner Prototype“Master Mariner Prototype”
Reference24002.42“24002.42”
MovementAutomatic caliber 906“automatic caliber 906”
Case materialStainless steel“Stainless steel”
DialSilver linen dial“Silver linen dial”

Visible details

  • Silver linen dial with black baton hour markers and a red central seconds hand.
  • Day-date display window at 3 o'clock displaying French text and numerals.
  • Case back features the 'JL' logo and text stating it is a prototype in English, French, and German.
  • Stainless steel case with a brushed finish on the front.

Research qualifications

  • Prototype status is described as a possibility or belief rather than a confirmed fact.
  • Specific movement serial number is not provided in the text, though it is described as corresponding to a 1972-1973 date range.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

1970s Jaeger-LeCoultre Master Mariner Chronometer - Prototype (Ref. 24002.42)

Reviewed 2026-11-02 · Record ce5aabd6cc

Terms in this record

Glossary explanations for terms named in this object’s record.

Other automatic wristwatch records